This invention relates to an air stone for dispensing bubbles of a gas into a fluid and, more particularly, to an air stone for dispensing air into the water of an aquarium, and wherein the air stone is configured with an extended interior chamber with a barrier for improved dispersion of the air throughout the stone.
Air stones are employed frequently for aerating the water of an aquarium to provide oxygen for fish and other marine life which may be present in the aquarium. The air stone is constructed of a body of porous material through which air can propagate and, in a typical installation in an aquarium, is connected via a flexible air tubing to an air pump located outside of the aquarium. The pump pumps air via the tubing into the air stone which disperses the air to form a stream of bubbles which migrate upwardly through the water. The air stone may also be placed within the lift tube of an aquarium undergravel filter to allow an entrained stream of bubbles to draw water through the lift tube and, thereby, circulate water through the filter.
It is noted that the construction of the air stone permits its use in situations, other than that of the fore-going aquarium, in which it is desired to disperse a gas within a fluid. However, for purposes of demonstrating the use of the invention, it is presumed that the air stone is to be employed for aeration of water in an aquarium.
A problem arises in the construction of air stones in that air forced into the stone tends to propagate through a portion of the porous material of the stone located generally in the vicinity of the air inlet to the stone, while the remaining portion of the body of porous material is essentially inactive in the process of dispersing the air. As a result, there is a significant diminution in the esthetic appearance to the paths of bubbles emanating from the air tone because the bubbles emanate only from the upper portion of the stone rather than emanating uniformly from the entire exterior surface of the stone. In addition, there is usually a mineral build up at the end of the air inlet into the stone which starts to clog after a while. Also, since the path of air is only through the upper part of the stone, the underutilization of the lower portion of the air stone results in a more rapid clogging and wearing of the upper portion of the air stone resulting in the more frequent need for replacing the air stone.
Frequently, it is desirable to use large air stones in the aquarium in order to prevent riding up of the tubing. However, in using the large air stones the aesthetic appearance is worsened since the air bubbles out from only the very top of the air stone because of its large size and because the air seeks the shortest path of resistance through the stone. One solution of extending the flow of bubbles to emanate along the length of the air stone is to use a more dense air stone. However, in doing so you require more pressure from the pump to drive the high density air stone.